Keep contrast low and adjust brightness so you don't lose too much detail in dark areas of the screen. These 2 controls are actually sorta mislabelled anyway.
Contrast (or Picture on a Sony) is actually white level, or how bright whites are. The higher you set this the brighter whites are. Turning this up too high overdrives the phosphors on the crts and can cause burn-in with stationary images.
Brightness should more properly be called Black level, or how dark blacks are. It's sorta backwards, the lower you set this the darker blacks are.
Set contrast first at a decently low level then adjust brightness until you just start to lose detail in extremely dark parts of the picture, or better yet use a calibration disc like AVIA or Video Essentials.
my set is calibrated with AVIA and the Xbox is a little darker than the DVD setting..I have to turn up the picture and brightness about 5 clicks on both settings for it to be perfect..I have some pictures of RS3 in my signature..one is without the flash..the difference in picture is incredible on an HDTV..